How to Implement AVEVA historian redundant servers on top of a redundant plant SCADA server architecture with one control client,

A single connection is active. The connector leverages the built-in trend, string variable and alarms and event redundancy of Plant Scada. Plant Scada currently does not support dual threads, one each for the historians and its partner.

The historians in a redundant setup are not intended to be a synchronized pair, where both the historian configuration and data are fully and automatically synchronized. It is up to you to make sure that the two historians are symmetrical and synchronized.

In case of Application server, it can be configured to automatically send data to both the primary historian and the specified partner. If one of the historians goes offline, the AppEngine stores the historized data until the historian comes back online. After the connection is restored, the AppEngine forwards the data to the historian that was offline. The Historian

Client automatically detects and selects the online Historian from the redundant pair.

Aveva Historian Standard - unlimited under flex license includes redundancy. 

A single connection is active. The connector leverages the built-in trend, string variable and alarms and event redundancy of Plant Scada. Plant Scada currently does not support dual threads, one each for the historians and its partner.

The historians in a redundant setup are not intended to be a synchronized pair, where both the historian configuration and data are fully and automatically synchronized. It is up to you to make sure that the two historians are symmetrical and synchronized.

In case of Application server, it can be configured to automatically send data to both the primary historian and the specified partner. If one of the historians goes offline, the AppEngine stores the historized data until the historian comes back online. After the connection is restored, the AppEngine forwards the data to the historian that was offline. The Historian

Client automatically detects and selects the online Historian from the redundant pair.

Aveva Historian Standard - unlimited under flex license includes redundancy.